Who will be joining Ellie in The Last of Us Part II?

The Last of Us: Part II is the development and while it has been confirmed that Ellie will be the new lead protagonist in this sequel it has been confirmed that she'll have a companion but Naughty Dog isn't saying who.

Well, so, Ellie used to be an NPC, but she’s the protagonist in this story, so the player is controlling Ellie. Umm, it’s safe to say with the game that we made in the past that there will be some NPC with you in this story, even though we’re not showing [the NPC] in this demo.

Many would assume Joel would be this companion but considering that Joel is very old during The Last of Us: Part II it's much more likely that this is a new character.